Film director George Miller's apocalyptic road action franchise "Mad Max" introduced the fascinating world of "war rigs" ― scrappy vehicles running on nitrogen-boosted engines and designed to fire archaic weapons such as harpoons and flame throwers.

These makeshift vehicles are actually made and used by non-government military groups across the world.

Groups like the Islamic State get their hands on whatever they can to supply their needs in combat.

The terrorists' reign in Mosul, its last holdout in Iraq, is nearing an end as they battle the country's army and U.S.-led coalition forces.

But their resistance with heavy weapons and suicide bombers continues.

Pictures show fighters in the Middle East utilizing Kia pick-ups as their war-rigs. / Courtesy of 1boon.kakao.com

Among the terrorist group's critical equipment are Korean trucks, according to photos and videos online.

ISIS was previously said to have favored Toyotas, but a Korean journalist/military expert said ISIS preferred Korean vehicles like Hyundai and Kia because they had bigger loading capacity and withstood heavy weights better than the Japanese vehicles.

A photo of white Hyundai pick-up shows a man maneuvering a flak gun on its deck.

In videos, other trucks alleged Korean products carry a Grad multiple launch rocket system and a 23-milimeter cannon.

Fighters ride on a pick-up that even shows a Korean driving school's name and contact number on its side.

A truck is written a Korean driving school's name and contact number on its side.

Mighty Hyundai dump truck fires a 122-milimeter missile.

A man sits behind a flak gun on a Hyundai pick-up.

"These ‘technical trucks,' a symbol of guerilla warfare, originated from the war in Somalia in 1991 when armed forces were hired by international human right agencies in the country to protect their safety," Yoo Yong-won said on Chosun Ilbo's internet platform.

"The forces were then given ‘technical assistance grants', which they used to buy off-road trucks and weapons and to upgrade their equipment."

Other military forces like Hezbollah, Taliban and Syrian rebels had also been seen using Korean trucks, Yoo said.